JP6072023B2 - Electron beam apparatus and method for manufacturing electron beam apparatus - Google Patents

Description

  The present invention relates to an electron beam apparatus and a method for manufacturing the electron beam apparatus.

  A typical electron beam device includes a sealed, ie, vacuum-tight, body portion within which a cathode housing is disposed. The cathode housing comprises a filament that is heated by an electric current to generate electrons. Thus, the generated electrons are accelerated by the high potential and exit through the exit window of the body, which is typically a thin window foil supported on a support grid. Electron beam devices may be used for several purposes, such as curing inks or adhesives, or sterilizing capacities or surfaces. The shape of the electron beam apparatus changes depending on application characteristics such as acceleration voltage and beam profile. The teachings of the present invention can be advantageously applied to electron beam devices used for the sterilization of textile wrapping materials because the performance of electron beam devices designed for that purpose can be greatly improved. It is. However, it should be understood that it can be applied to other electron beam devices having a similar structure.

  In the field of sterilization of textile packaging materials, performance factors such as stability, durability, and lifetime are important issues if the quality of sterilization is ensured. All the aforementioned components and further components can be optimized in order for the electron beam device to produce the desired beam shape in any given situation.

  The present invention relates to the background of elongated e-beam devices used to treat larger surfaces, such as textile packaging materials used in the production of packaging containers. More specifically, the present invention relates to an improvement of the above electron beam apparatus in terms of simplifying the assembly of the electron beam apparatus while ensuring appropriate quality.

  The present invention relates to an electron beam apparatus including an elongated cylindrical body, wherein the electron exit window extends in the longitudinal direction of the cylindrical body. The cylinder at least partially forms a vacuum chamber, the vacuum chamber generating a cathode having an elongated cathode housing, and a control grid and electrons extending together along the elongated shape of the cathode housing. And a filament. The control grid and cathode housing are connected to each other by connecting means, and the free longitudinal end portions of either the control grid or cathode housing form a bulge shape to form an electron beam forming electrode. In order to bend each other. This approach provides an electron beam device that has a cathode that is easily manufactured and assembled and that can form an electric field so that electrons reach the electron exit window in a direction that is essentially orthogonal to the plane of the electron exit window. . With the electron beam device according to the invention, an electron beam very suitable for sterilizing, for example, wide woven packaging materials is formed.

  In one embodiment, the control grid comprises an essentially centrally perforated surface through which electrons can pass, and the longitudinal ends of either the control grid or the cathode housing are bulge-like shapes. ) Are bent on the control grid in the direction towards each other so that they extend to the longitudinal boundary of the perforated surface. The bulge shape will help form the electric field so that the electrons reach the exit window in a direction essentially perpendicular, ie, essentially perpendicular to the plane of the exit window. In fact, the electrode causes the electron trajectory to “bend” slightly to the center of the electron beam, so that it is usually closer to the exit window where the electron trajectory tends to spread, i.e., closer to the control grating. In the vicinity of the exit window that will be more widened, the electron trajectory will act in the opposite direction of “curving”.

  In one embodiment, the bulge shape is formed such that its free edge faces in a direction essentially perpendicular to the perforated surface of the control grid. Its free edge essentially extends down to the control grid. This further adds to the effect of directing the electrons.

  In one embodiment, the longitudinal terminations that are bent to form a bulge shape are bent over the connecting means to at least partially surround the connecting means. Therefore, the shape of the connecting means has no or little influence on the electric field and can therefore be designed in the best way that can connect the cathode housing and the control grid.

  In order to direct the electrons uniformly to the control grid, the cathode housing is preferably formed as an elongated semi-annular outer shell, the open side of the outer shell being covered by the control grid.

  In one or more presently preferred embodiments, the at least one filament extends along the outer shell essentially centrally within the semi-annular outer shell. This embodiment provides a cathode that is small and easy to assemble.

  In one embodiment, the bulge shape is formed by a control grid, and the free longitudinal termination of the cathode housing is bent inward and is a radial protrusion oriented essentially parallel to the perforated surface of the control grid. The connecting means is connected to the projection of the cathode housing and also to the region of the control grid, and this region is provided between the perforated surface and the bulging shape. According to this embodiment, the parts of the cathode can be easily manufactured and assembled.

  In one embodiment, the control grid and cathode housing are connected to separate power sources and the coupling means is an electrically insulating element. This embodiment will form a triode type electron beam device in which the control grating actively shapes the electron beam.

  In one embodiment, the electron beam device is of the triode type, the filament is connected to a first power source, the cathode housing is connected to a second power source, the control grid is connected to a third power source, and a cylindrical body And the electronic exit window is grounded. This is an example of an efficient triode-type electron beam device.

  Further embodiments are defined by the additional dependent claims.

  Furthermore, the present invention also provides an electron beam apparatus comprising an elongated cylindrical body, wherein the electron exit window extends in the longitudinal direction of the cylindrical body. The cylinder at least partially forms a vacuum chamber, the vacuum chamber generating a cathode having an elongated cathode housing, and a control grid and electrons extending together along the elongated shape of the cathode housing. And a filament. In this method, the control grid and the cathode housing are connected to each other by a connecting means, and the free longitudinal end portions of either the control grid or the cathode housing are formed to form a bulge shape for forming an electron beam forming electrode. To bend each other in a direction toward each other.

  In the following, presently preferred embodiments of the invention will be described in more detail with reference to the accompanying schematic drawings.

1 is a perspective view of an electron beam apparatus according to an embodiment of the present invention. It is a perspective view of the cathode which can be used with the electron beam apparatus of FIG. FIG. 3 is a cross-sectional view in the longitudinal direction of the cathode of FIG. 2. FIG. 3 is a schematic cross-sectional view of a first embodiment of the cathode of FIG. 2. FIG. 6 is a view of a connecting means for connecting the control grid to the cathode housing. FIG. 4 is a diagram of holes used in the control grid and cathode housing to connect the connecting means, with dotted lines showing the maximum diameter of the connecting means in two states, an installed state and a fixed state. It is a perspective view of a part of cathode housing. It is a one part perspective view of a control grid. It is a schematic sectional drawing of 2nd Embodiment of a cathode. It is a schematic sectional drawing of 3rd Embodiment of a cathode.

  FIG. 1 is a perspective view of an exemplary sealed electron beam device 100 of the present invention, showing only its appearance. The purpose of the drawings is merely to illustrate the basic components of an electron beam device, and that purpose is not to provide an accurate structural drawing, nor in any other way to limit the invention. It must be emphasized that it is not a provision.

  The main component of the electron beam apparatus is an elongated cylindrical body 102. The exit window 104 provides an exit for electrons from the vacuum inside the cylinder 102. The exit window 104 further includes a sub-assembly that is not related to the present invention, but has a feature that provides an exit window for electrons while maintaining a vacuum inside the cylindrical body 102. The proximal end of the cylindrical body 102 comprises an assembly comprising an electrical connection 106 and an insulating ceramic disc 108, which seals the assembly and the inner periphery of the cylindrical body 102. . In the present embodiment, the ceramic disk 108 actually seals the inner periphery of the cylindrical member 110 welded to the elongated cylindrical body. This configuration simplifies the assembly, disassembly, and reassembly of the electron beam device since it is not relevant to the present invention.

  A cathode is disposed inside the cylindrical body 102. The cathode includes a cathode housing 112, which is one of the components illustrated in FIGS. Cylindrical member 110 and ceramic disc 108 can be clearly seen, and those skilled in the art will understand how the illustrated arrangement is inserted into cylindrical body 102 to form the assembly of FIG. The cathode housing 112 is formed as a semi-circular outer shell, and its open side is covered with a control grid 114. Disposed within the semi-annular outer shell of the cathode housing 112 is one or more filaments 120 (see FIG. 3) that extend from the proximal end to the distal end of the cathode housing 112. In use, the electron beam uses current to heat the filament 120 and accelerate electrons toward the electron exit window 104 by a high potential between the cathode housing 112 and the exit window 104 (which is the anode). Generated. The high potential is created, for example, by connecting the cathode housing to a power source and grounding the cylinder.

  By applying a potential also to the control lattice 114, electron emission can be further suppressed. When a separate and changeable potential is applied to the control grid 114, it allows the control grid 114 to be used to actively shape the generated electron beam. For this purpose, the control grid 114 may be electrically connected to a separate power source (not shown). This type of electron beam device is commonly referred to as a triode. Triodes are generally characterized in that the filament is connected to a first power source, the cathode housing is connected to a second power source, and the control grid is connected to a third power source.

  The control grid 114 includes a flat perforated surface 115 having a pattern of openings or through holes for the passage of electrons. The open side of the cathode housing 112 supports the control grid 114 and should face the exit window 104 for obvious reasons.

A first embodiment of the cathode is shown in FIG. Free longitudinal end portions of the cathode housing 112 are bent inward in the direction toward each other, i.e., in the short direction perpendicular to the edges extending in the longitudinal direction. Thereby, the edge forms a radial projection 116. These radial projections 116 are preferably parallel and straight to the flat perforated surface 115 of the control grid 114. The control grid 114 is connected to the protrusion 116 at the connecting position using the connecting means 118. Where there is a potential difference between the cathode housing 112 and the control grid 114, the connecting means 118 is preferably an electrically insulating element. In such a case, the electrical insulation element is preferably made of, for example, the ceramic material Al ₂ O ₃ .

  An example of the connecting means 118 is shown in FIG. The connecting means 118 is rotationally symmetric around the X axis. The connecting means 118 comprises three larger diameter portions and two smaller diameter intermediate portions. The middle part of the larger diameter part is larger than the other two larger diameter parts. The control grid and the cathode housing are connected to each other by a connecting means 118 through a hole. A typical hole shape 144 is shown in FIG. It should be pointed out that FIGS. 5a and 5b are not on the same scale. The hole 144 includes a larger diameter circular portion 122 and a smaller diameter oval portion 124. The larger diameter of the circular portion 122 is slightly larger than the second largest diameter of the connecting means 118. The smaller diameter of the oval 124 is slightly less than or essentially equal to the smaller diameter of the intermediate portion of the connecting means 118. In FIG. 6a, a portion of the cathode housing 112 is shown clearly visible with radial projections 116. FIG. The radial projection 116 is provided with a through hole having the above-described hole shape 144 shown in FIG. A plurality of such holes 144 are provided along radial projections 116 extending in the longitudinal direction. Similarly, a plurality of such holes 144 are provided in the control grid 114. The holes 144 are disposed in a region provided between the perforated surface 115 and the bulge-like shapes 126, the bulge shapes being described in more detail below. Note that FIG. 6 b shows the control grid “upside down” so that the perforated surface 115 adapted to face the cathode housing can be clearly seen. Further, for the sake of simplicity, the perforated surface 115 is shown here blank (the pattern of through openings for electrons cannot be seen).

  The connecting means 118 is attached to the hole 144 by passing the end of the connecting means 118 through the larger circular part 122 of the hole 144. Therefore, the radial surface with the largest diameter of the connecting means 118 is placed on the surface around the hole 144 in the protrusion 116. Thereby, the connecting means 118 is in an attached state. The connecting means 118 is then slid towards the smaller oval 124 of the hole 144 to which it is secured. This is a fixed state. The position of the connecting means 118 in the mounted state and in the fixed state is indicated by a dotted line in FIG. 5b. The control grid 114 and the cathode housing 112 are attached to each other by arranging one connecting means 118 in each hole 144 of the cathode housing 120 and sliding the connecting means 118 in a fixed state. Thus, the control grid 114 is arranged to receive the connecting means 118 attached to the cathode housing 112 at the other end in the larger circular portion of the hole 144 in the control grid 114. The control grid 114 is then slid into position over the cathode housing 112 so that the control grid 114 is finally positioned in the smaller oval portion 124 of the hole 144 in the control grid 114. Will be placed.

  In the first embodiment of the cathode shown in FIG. 4, the free long terminal ends 128 of the control grid 114 are bent in a direction toward each other, that is, in a short direction perpendicular to the extension of the long terminal ends. As a result, a bulging shape 126 for forming an electron beam forming electrode is formed. Such electrodes are sometimes referred to as “Wehnelt” electrodes. The bulging shape helps in the generation of a predictable smooth electric field and benefits the performance of the electron beam device 100. The bulging shape helps form an electric field so that the electrons reach the exit window 104 in a direction that is essentially perpendicular, ie, essentially perpendicular to the plane of the exit window 104. In fact, the electrode causes the electron trajectory to “bend” slightly to the center of the electron beam so that the electron trajectory is closer to the exit window 104 where the electron trajectory tends to expand, ie, closer to the control grating 114. In the vicinity of the exit window 104, which would normally be more widened, the electron trajectory will act opposite to “curving”.

  The term “bulging shape” should not be construed in a limited way, and in this specification, for example, a bulging shape, a ball-like shape, a rolled shape, a curved shape, a wave-like shape, Alternatively, it should be interpreted as any shape that forms a semicircular shape. Further, for example, it can mean a more linear shape such as a semi-triangular shape that is continuous in multiple ways.

  The control grid 114 is bent so as to be wound on the control grid 114 itself toward the perforated surface 115 positioned at the center thereof. The bulging shape 126 is made to extend to the longitudinal boundary 130 of the perforated surface 115. Further, the bulge shape 126 is formed such that its free edges 132 are oriented in a direction essentially perpendicular to the perforated surface 115 of the control grid 114. Its free edge 132 extends essentially down to the control grid 114, leaving only a small gap. As can be seen in FIG. 4, the longitudinal termination 128 is bent over the connecting means 118 to at least partially surround the connecting means 118.

  As shown in FIG. 2, the aforementioned cathode is fitted in an electron beam apparatus. Similar to the proximal end, the distal end of the cathode housing 112 includes a physical suspension for the filament 120 along with an electrical connection. At the distal end, this configuration is housed and covered in a hemispherical lid 134. Using a hemispherical lid will effectively shield the components inside the lid from the electric field outside the lid, and conversely, for example, the shape of the components inside the lid will This suggests that there will be no negative effects.

  As shown in FIG. 3, the lid 134 has a spherical outer shell shape with a part slightly exceeding the hemisphere in cross section. The lid 134 of this embodiment is axially symmetric, and a solid bulge 136 is provided at the free end. The bulge 136 also provides a smooth appearance to the free edge, so that the electric field strength is kept small. It will be. The opening of the lid 134 defined by the inner peripheral edge of the bulging portion 136 is dimensioned to fit into the semi-circular outer shell of the cathode housing 112 so that a portion of the cathode housing 112 can be inserted therein. ing. The opening of the lid 134 has a diameter that is a curvature of a semi-circular outer shell, and effectively closes the lower half of the opening. The upper half of the opening can be covered by a plate 138 to prevent the electric field from entering the lid 134 and position the cathode housing 112 relative to the lid 134. The lid 134 may be shown as comprising an integrally formed open end (provided with a free edge and a ball-like shape) and a hemisphere.

  At the proximal end, the cathode housing 112 is suspended in an elongated cylinder. This method of suspension may not be provided in one way, and the suspension best understood in FIG. 3 is an option not previously shown. The cathode housing is efficiently suspended in the central opening of the disk 108 by several intermediate parts not described in detail herein. In order to avoid distortion of the electric field at the proximal end, a lid is also provided at the proximal end, which will be referred to as “proximal lid” 140 in the following. The free edge at the open end of the proximal lid 140 is provided with a ball-like shape, and the open end itself is substantially equivalent to the corresponding end of the lid 134. However, while the lid 134 has been shown with an open end and a hemisphere, the proximal lid 140 has an open end so that it fits into the suspension component at the proximal end of the cylinder. And a cylindrical outer shell.

  Preferably, the cathode housing, cylinder and control grid are all made from stainless steel.

  2 and 4, the cross section of the semi-circular outer shell of the cathode housing 112 is not a smooth circle, but is formed by a small plane 142 or a continuous polygon. This considerably facilitates the bending process used in the manufacture of electron beam devices. Furthermore, the cathode housing 112 is provided with a number of support portions (not shown) that function as reinforcing members that intersect the elongated shape of the cathode housing 112.

  A second embodiment of the cathode is shown in FIG. For simplicity, the same reference numerals are used for corresponding elements and only the differences between the first and second embodiments will be described. As can be seen in the drawing, the second embodiment is very similar to the first embodiment. Basically, only the control grid 114 and its bulging shape 126 have different shapes. The control lattice 114 is bent so that the surface of the perforated surface 115 is displaced from the surface constituting the region where the hole 144 for the connecting means 118 is provided. The perforated surface 115 is shifted in a direction away from the cathode housing 112. This embodiment has a more complicated design than the first embodiment, but the electric field strength is smaller.

  A third embodiment of the cathode is shown in FIG. For simplicity, the same reference numerals are again used for corresponding elements, and only the differences between the first and third embodiments will be described. In the third embodiment, the free longitudinal end portions of the cathode housing 112 are bent toward each other in order to form a bulging shape 126 for forming an electron beam forming electrode. A radial protrusion 116 adapted to hold the connecting means 118 is formed by an element 144 connected to the inner surface of the cathode housing 112. Element 144 may preferably be welded or brazed to the inner surface. Other alternative attachment methods include, for example, adhesive, riveting, or screwing. The element 144 allows the control grid 114 to be held in the same position as in the first embodiment.

  The present invention further includes a method of manufacturing the electron beam device 100 comprising the elongated cylindrical body 102, wherein the electron exit window 104 extends in the longitudinal direction of the cylindrical body 102. The cylindrical body 102 at least partially forms a vacuum chamber. The vacuum chamber includes therein a cathode having an elongated cathode housing 112, a control grid 114 extending together along the elongated shape of the cathode housing 112, and at least one filament 120 for generating electrons. Yes. In this method, the control grid 114 and the cathode housing 112 are connected to each other by the connecting means 118, and the free longitudinal end portions 122 of either the control grid 114 or the cathode housing 112 are formed to form an electron beam forming electrode. Bending in the direction toward each other to form a bulge shape.

  Although the invention has been described with reference to the presently preferred embodiment, it will be understood that various modifications and changes may be made without departing from the purpose and scope of the invention as defined in the appended claims. Will.

DESCRIPTION OF SYMBOLS 100 Electron beam apparatus 102 Cylindrical body 104 Electron exit window 106 Electrical connection part 108 Ceramic disk 110 Cylindrical member 112 Cathode housing 114 Control lattice 115 Perforated surface 116 Protrusion 118 Connecting means 120 Filament 122 Circular part 124 Oval part 126 Swelling shape 128 Longitudinal end portion 130 Longitudinal boundary portion 132 Free edge 134 Lid 136 Bumped portion 138 Plate 140 Proximal lid 142 Small plane 144 Hole

Claims (13)

An electron beam apparatus comprising a circular cylindrical body (102) (100), said cylindrical body (102) is provided with an electronic exit window (104) that Mashimasu extending in the axial direction of the cylindrical body (102), the cylinder (102) forms at least a partial vacuum chamber, the vacuum chamber, a cathode having a mosquito cathode housing (112), shape the along both extending control of the cathode housing (112) A grid (114) and at least one filament (120) for generating electrons, and the control grid (114) and the cathode housing (112) are coupled to each other by coupling means (118), the control grid (114) comprises a perforated surface (115) through which the electrons can pass;
Free termination portions in the axial direction of the control grid (114) is, in order to form a bulged shape to form an electron beam forming electrode (126), bent in a direction towards each other,
The connecting means (118) is an electrically insulating element and is disposed in a region provided between the perforated surface (115) and the bulging shape (126),
The bulging shape (126) is bent over the connecting means (118) to at least partially surround the connecting means (118), and both free edges in the axial direction of the control grid (114) ( 132) is formed so as to face a direction perpendicular to the perforated surface (115) of the control grating (114 ). The perforated surface of the control grid (114) (115) is disposed Hisashi Naka, free end portions in the axial direction of the control grid (114), said bulged shape (126) is the foraminous surface boundary portion in the axial direction of the (115) so as to extend to (130), is bending in a direction toward each other, the electron beam apparatus according to claim 1 (100). The opposite free edges of the control grid (114) (132) extends until said foraminous surface (115), the electron beam apparatus according to claim 2 (100). The cathode housing (112) is formed as a shell of semicircular annular, wherein the side that open shell is covered by said control grid (114), according to any one of claims 1 3 Electron beam device (100). Wherein the at least one filament (120), according to the cathode housing (112) claim 4 which extends along the outer shell of the semicircular annular in middle of the outer shell of semicircular annular Electron beam device (100). Free end ends in the axial direction before Symbol cathode housing (112) is bent inwardly, perforated surface in the radial direction directed towards the flat row projections of said control grid (114) and (116) forming, electron beam apparatus according to any one of the 5 請 Motomeko 2 (100). Wherein A said control grid (114) cathode housing (112), Ru is connected to a separate power source, the electron beam device according to any one of the 請 Motomeko 1 6 (100). The electron beam device (100) is of a triode type, the filament (120) is connected to a first power source, the cathode housing (112) is connected to a second power source, and the control grid (114 ) is connected to the third power, the cylindrical body (102) and the electron exit window (104) is grounded, electron beam apparatus according to claim 7 (100). The cathode housing (112) is made from stainless steel, an electron beam device according to any one of claims 1 8 (100). It said control grid (114) is made from stainless steel, an electron beam device according to any one of claims 1 9 (100). It said cylindrical body (102) is made from stainless steel, an electron beam device according to any one of claims 1 10 (100). It said connecting means (118) is made from a ceramic material, an electron beam device according to any one of claims 1 11 (100). An electron beam apparatus comprising a circular cylindrical body (102) (100), said cylindrical body (102) is provided with an electronic exit window extending in the axial direction of the cylinder (102) (104), said cylindrical body (102) forms at least a partial vacuum chamber, the vacuum chamber, mosquitoes and cathode having a cathode housing (112), the cathode housing (112) both extending control grid along a shape of ( 114) and at least one filament (120) for generating electrons, and the control grid (114) comprises an electron beam device (100) comprising a perforated surface (115) through which the electrons can pass. A method of manufacturing, the method comprising:
Free termination portions in the axial direction before Symbol control grid (114), to form a bulged shape to form an electron beam forming electrode, a step of bending in the direction towards each other,
Forming the bulging shape (126) such that both free edges (132) in the axial direction of the control grid (114) face a direction perpendicular to the perforated surface (115) of the control grid (114); ,
Connecting the control grid (114) and the cathode housing (112) to each other by connecting means (118), the connecting means (118) comprising the perforated surface (115) and the bulging shape (126); ), And the bulging shape (126) is bent over the connecting means (118) to at least connect the connecting means (118). wherein the containing portion surrounding the steps, a.

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